Condensed polycyclic compound and organic light-emitting device using the same

ABSTRACT

A new condensed polycyclic compound represented by general formula [I]: 
                         
wherein R 1  is hydrogen, halogen, cyano, a substituted amino or a group selected from the group consisting of alkyl, aralkyl, aryl, heterocyclic, each having no substituent or a substituent; and Ar 1  to Ar 5  are the same or different and are each independently a condensed polycyclic aromatic group or a condensed polycyclic heterocyclic group, each having no substituent or a substituent is used for an organic light-emitting device that is extremely efficient in a light output with high luminance and is extremely durable.

TECHNICAL FIELD

The present invention relates to a new organic compound and an organiclight-emitting device using the same.

BACKGROUND ART

An organic light-emitting device is a device in which a thin filmcontaining a fluorescent organic compound or a phosphorescent organiccompound is sandwiched between an anode and a cathode; an exciton of thefluorescent compound or the phosphorescent compound is produced byinjecting an electron or a hole from each of the electrodes and thelight radiated when the exciton returns to the ground state is utilized.

In a research by Eastman Kodak Company in 1987 (Appl. Phys. Lett. 51,913 (1987)), there is reported a light emission of about 1,000 cd/m² atan applied voltage of about 10 V for a device of separated-functiontwo-layered structure using ITO for anode and a magnesium-silver alloyfor cathode, respectively, an aluminum-quinolinol complex as anelectron-transporting material and a light-emitting material and atriphenylamine derivative as a hole transporting material. Relatedpatents include U.S. Pat. No. 4,539,507; U.S. Pat. No. 4,720,432 andU.S. Pat. No. 4,885,211.

In addition, light-emission from ultraviolet to infrared is possible bychanging the type of fluorescent organic compounds and researches ofvarious compounds have been conducted actively recently. For example,they are described in U.S. Pat. Nos. 5,151,629; 5,409,783; 5,382,477;5,130,603; 6,093,864; 5,227,252; Japanese Patent Application Laid-OpenNo. H05-202356; Japanese Patent Application Laid-Open No. H09-202878 andJapanese Patent Application Laid-Open No. H09-227576.

In recent years, there have been a number of studies in whichphosphorescent compounds are used as a light-emitting material and theenergy in a triplet state is used for an EL emission. A group ofPrinceton University has reported that an organic light-emitting deviceusing an iridium complex as a light-emitting material exhibits a highlight-emitting efficiency (Nature 395, 151 (1998)).

Moreover, a group of Cambridge University has reported (Nature 347, 539(1990)) an organic light-emitting device using a conjugated polymerother than the organic light-emitting device using monomeric materialsas described above. In this report the light-emission in a monolayer isconfirmed by forming a film of polyphenylenevinylene (PPV) in a coatingsystem.

The related patents on organic light-emitting devices using conjugatedpolymers include U.S. Pat. Nos. 5,247,190; 5,514,878; 5,672,678;5,317,169; 5,726,457 and Japanese Patent Application Laid-Open No.H05-247460.

Thus, recent progress in organic light-emitting devices is remarkable,and possibilities for a wide range of applications are indicated sinceit is characterized in that a thin and light-weight light-emittingdevice having high luminance at a low applied-voltage, diversity oflight-emitting wavelength and high-speed response can be prepared.

However, a higher-luminance light output or high conversion efficiencyis required under present circumstances. In addition, there are numbersof problems in terms of durability such as the variation with timeduring use for a long period of time and the deterioration due to anatmospheric gas containing oxygen or humidity. Moreover, thelight-emission of blue, green and red having a good color purity isrequired for applications such as a full-color display, but these issuesare not sufficiently satisfied.

Aromatic compounds and condensed polycyclic aromatic compounds have beenstudied in great numbers as fluorescent organic compounds to be used foran electron-transporting layer or a light-emitting layer. These include,for example, Japanese Patent Application Laid-Open No. H04-68076;Japanese Patent Application Laid-Open No. H05-32966; Japanese PatentApplication Laid-Open No. H06-228552; Japanese Patent ApplicationLaid-Open No. H06-240244; Japanese Patent Application Laid-Open No.H07-109454; U.S. Pat. No. 6,203,933; Japanese Patent ApplicationLaid-Open No. H09-241629; U.S. Pat. No. 6,387,547; U.S. Pat. No.6,399,223 and Japanese Patent Application Laid-Open No. 2000-268964.However, nothing that sufficiently satisfies light-emission luminanceand durability has been obtained so far.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide a new condensedpolycyclic compound.

It is a further object of the present invention to provide an organiclight-emitting device having a light output with an extremely highefficiency and high luminance using a specific condensed polycycliccompound.

It is a further object of the present invention to provide an extremelydurable organic light-emitting device.

It is a further object of the present invention to provide an organiclight-emitting device that is easily produced and can be prepared at arelatively low cost.

Specifically, the present invention provides a condensed polycycliccompound represented by general formula [I] or [II]:

wherein R₁ is hydrogen, halogen, cyano, a substituted amino or a groupselected from the group consisting of alkyl, aralkyl, aryl,heterocyclic, each having no substituent or a substituent; and Ar₁ toAr₅ are the same or different and are each independently a condensedpolycyclic aromatic group or a condensed polycyclic heterocyclic group,each having no substituent or a substituent; and

wherein Ar₆ to Ar₁₁ are the same or different and are each independentlya group selected from the group consisting of condensed polycyclicaromatic groups and condensed polycyclic heterocyclic groups, eachhaving no substituent or a substituent.

The present invention further provides an organic light-emitting devicecomprising a pair of electrodes consisting of an anode and a cathode andorganic compound-containing layers sandwiched between the pair ofelectrodes, wherein at least one layer of the organiccompound-containing layers contains at least one compound selected fromthe group consisting of the condensed polycyclic compounds.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view illustrating one example of the organiclight-emitting device according to the present invention;

FIG. 2 is a sectional view illustrating another example of the organiclight-emitting device according to the present invention;

FIG. 3 is a sectional view illustrating another example of the organiclight-emitting device according to the present invention;

FIG. 4 is a sectional view illustrating another example of the organiclight-emitting device according to the present invention;

FIG. 5 is a sectional view illustrating another example of the organiclight-emitting device according to the present invention; and

FIG. 6 is a sectional view illustrating another example of the organiclight-emitting device according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will now be described in detail.

The condensed polycyclic compounds of the present invention will befirst described.

The condensed polycyclic compounds of the present invention arerepresented by the above general formula [I] or [II].

Herein, at least one of Ar₁ to Ar₅ or at least one of Ar₆ to Ar₁₁ ispreferably a condensed polycyclic aromatic group represented by generalformula [III]:

wherein R₂ is hydrogen, halogen, cyano, a substituted amino or a groupselected from the group consisting of alkyl, aralkyl, aryl andheterocyclic, each having no substituent or a substituent; and R₃ and R₄are the same or different and are each independently hydrogen or a groupselected from the group consisting of alkyl, aralkyl, aryl andheterocyclic, each having no substituent or a substituent.

Further, the condensed polycyclic compounds of the present invention aremore preferably represented by any of general formulas.

Furthermore, at least one of Ar₁ to Ar₅ or at least one of Ar₆ to Ar₁₁preferably denotes a condensed polycyclic aromatic group represented byany of general formulas [IV] to [VII]:

wherein R₅ to R₈ are hydrogen, halogen, cyano, a substituted amino or agroup selected from the group consisting of alkyl, aralkyl, aryl andheterocyclic, each having no substituent or a substituent.

Specific examples for the substituent groups in the above generalformulas [I] to [VII] are shown below.

The alkyl group includes methyl, ethyl, n-propyl, iso-propyl, n-butyl,ter-butyl, octyl or the like.

The aralkyl group includes benzyl, phenethyl or the like.

The aryl group includes phenyl, biphenyl, terphenyl or the like.

The heterocyclic group includes thienyl, pyrolyl, pyridyl, oxazolyl,oxadiazolyl, thiazolyl, thidiazolyl, terthienyl or the like.

The substituted amino group includes dimethylamino, diehtylamino,dibenzylamino, diphenylamino, ditolylamino, dianisolylamino or the like.

The halogen atom includes fluorine, chlorine, bromine, iodine or thelike.

The condensed polycyclic aromatic group includes fluorenyl, naphthyl,fluoranthenyl, anthryl, phenathryl, pyrenyl, tetracenyl, pentacenyl orthe like.

The condensed polycyclic heterocyclic group includes quinolyl,diazafluorenyl, acrydinyl, phenanthrolyl or the like.

The substituent groups that the above substituent groups may haveinclude alkyl groups such as methyl, ethyl and propyl; aralkyl groupssuch as benzyl and phenethyl; aryl groups such as phenyl and biphenyl;heterocyclic groups such as thienyl, pyrolyl and pyridyl; amino groupssuch as dimethylamino, diethylamino, dibenzylamino, diphenylamino,ditolylamino and dianisolylamino; alkoxyl groups such as methoxyl,ethoxyl, propoxyl and phenoxyl; cyano group and halogen atoms such asfluorine, chlorine, bromine and iodine.

The followings are typical examples of the condensed polycycliccompounds of the present invention, but the present invention is notlimited thereto:

The condensed polycyclic compounds of the present invention can besynthesized by generally known methods, and can be obtained by synthesismethods such as, for example, Suzuki coupling method using a palladiumcatalyst (e.g., Chem. Rev. 1995, 95, 2457-2483); Yamamoto method using anickel catalyst (e.g., Bull. Chem. Soc. Jpn. 51, 2091, 1978) and asynthesizing method using aryltin compounds (e.g., J. Org. Chem., 52,4296, 1987).

The condensed polycyclic compounds of the present invention areexcellent in an electron-transporting property, a light-emittingproperty and durability compared with conventional compounds, and areuseful for an organic compound-containing layer, in particular, anelectron-transporting layer and a light-emitting layer in an organiclight-emitting device. In addition, the layer formed by a vacuumdeposition process or a solution coating process hardly causescrystallization or the like and is excellent in the stability with time.

The organic light-emitting device of the present invention will now bedescribed in detail.

The organic light-emitting device of the present invention at leastcomprises a pair of electrodes consisting of an anode and a cathode andone or a plurality of organic compound-containing layers sandwichedbetween the pair of electrodes, wherein at least one layer of theabove-described organic compound-containing layers contains at least onecompound selected from the group consisting of the condensed polycycliccompounds represented by the above general formula [I] or generalformula [II].

In the organic light-emitting device of the present invention, at leastthe electron transporting layer or the light-emitting layer among theorganic compound-containing layers preferably contains at least oneselected from the group consisting of the above-described condensedpolycyclic compounds.

In the organic light-emitting device of the present invention, thecondensed polycyclic compounds represented by the above general formula[I] or general formula [II] are formed between the anode and the cathodeby a vacuum deposition process or a solution coating process. Theorganic layer is preferably formed in a thin film having a thickness ofless than 10 μm, preferably 0.5 μm or less, more preferably from 0.01 to0.5 μm.

The organic light-emitting device of the present invention comprises apreferred embodiment that at least the light-emitting layer of theorganic compound-containing layers contains at least one selected fromthe group consisting of the condensed polycyclic compounds and afluorene compound represented by general formula [VIII] or [IX]:

wherein R₉ and R₁₀ are the same or different and are each independentlyhydrogen or a group selected from the group consisting of alkyl,aralkyl, aryl and heterocyclic, each having no substituent or asubstituent; any pair of R₉ combined to their respective fluorenestructures are the same or different to each other; any pair of R₁₀combined to their respective fluorene structures are the same ordifferent to each other; R₁₁ and R₁₂ are the same or different and areeach independently hydrogen, halogen, cyano or a group selected from thegroup consisting of alkyl, aralkyl, aryl and heterocyclic, each havingno substituent or a substituent; any pair of R₁₁ combined to theirrespective fluorene structures are the same or different to each other;any pair of R₁₂ combined to their respective fluorene structures are thesame or different to each other; Ar₁₂, Ar₁₃, Ar₁₄ and Ar₁₅ are the sameor different and are each independently a group selected from the groupconsisting of aromatic, heterocyclic, condensed polycyclic aromatic andcondensed polycyclic heterocyclic, each having no substituent or asubstituent, and Ar₁₂ and Ar₁₄ can be bonded to Ar₁₃ and Ar₁₅respectively to form a ring; and n is an integer from 1 to 10, and

wherein R₁₃ and R₁₄ are the same or different and are each independentlyhydrogen or a group selected from the group consisting of alkyl,aralkyl, aryl and heterocyclic, each having no substituent or asubstituent; any pair of R₁₃ combined to their respective fluorenestructures are the same or different to each other; any pair of R₁₄combined to their respective fluorene structures are the same ordifferent to each other; R₁₅ and R₁₆ are the same or different and areeach independently hydrogen, halogen, cyano or a group selected from thegroup consisting of alkyl, aralkyl, aryl and heterocyclic, each havingno substituent or a substituent; any pair of R₁₅ combined to theirrespective fluorene structures are the same or different to each other;any pair of R₁₆ combined to their respective fluorene structures are thesame or different to each other; Ar₁₆ and Ar₁₇ are the same or differentand are each independently a divalent group selected from the groupconsisting of divalent aromatic and divalent heterocyclic, each havingno substituent or a substituent; Ar₁₈, Ar₁₉, Ar₂₀ and Ar₂₁ are the sameor different and are each independently a group selected from the groupconsisting of aromatic, heterocyclic, condensed polycyclic aromatic andcondensed polycyclic heterocyclic, each having no substituent or asubstituent, and Ar₁₈ and Ar₂₀ can be bonded to Ar₁₉ and Ar₂₁respectively to form a ring; and m is an integer from 1 to 10.

Examples of the substituent groups in the general formulas [VIII] and[IX] are similar to those in the above general formulas [I] to [VII].The followings are typical examples of the fluorene compoundsrepresented by the general formula [VIII] or [IX], but the presentinvention is not limited thereto:

FIGS. 1 to 6 illustrate preferred examples of the organic light-emittingdevices of the present invention.

The example of FIG. 1 has the structure in which an anode 2, alight-emitting layer 3 and a cathode 4 are provided on a substrate 1 inthis order. The light-emitting device herein used is useful when it hasa hole-transporting capability, an electron-transporting capability andlight-emitting performance singly within itself, or when compoundshaving respective characteristics are mixed for use.

The example of FIG. 2 has the structure in which an anode 2, ahole-transporting layer 5, an electron-transporting layer 6 and acathode 4 are provided on a substrate 1 in this order. This example isuseful when a material having a hole-transporting capability and/or anelectron-transporting capability is used for respective layers as alight-emitting substance in combination with a mere hole-transportingsubstance or an electron-transporting substance having no light-emittingproperty. In this case, the light-emitting layer comprises thehole-transporting layer 5 or the electron-transporting layer 6.

The example of FIG. 3 has the structure in which an anode 2, ahole-transporting layer 5, a light-emitting layer 3, anelectron-transporting layer 6 and a cathode 4 are provided on asubstrate 1 in this order, a carrier-transporting function and alight-emitting function being separated. The separation of thelight-emitting layer from the charge-transporting layer extremelyincreases the freedom of material selection since a compound having eachproperty such as a hole-transporting property, an electron-transportingproperty or a light-emitting property can be used in a suitablecombination. For example, various compounds having differentlight-emitting wavelengths can be used to allow diversification of thehue of light emission. Further, it is also possible to try to improvethe efficiency of light emission by effectively confining each carrieror exciton in the central light-emitting layer 3.

The example of FIG. 4 has the structure in which a hole-injecting layer7 is inserted between the anode 2 and the hole-transporting layer 5 inthe form of FIG. 3, which is effective for improving adhesiveness of theanode 2 to the hole-transporting layer 5 or to improve a hole-injectingproperty, being effective to reduce voltage.

Examples of FIGS. 5 and 6 have the structure in which a layer forblocking a hole or an exciton from passing through to the side of thecathode 4 (hole-blocking layer 8) is inserted between the light-emittinglayer 3 and the electron-transporting layer 6 in the forms of FIGS. 3and 4. The use of a compound having a very high ionization potential asthe hole-blocking layer 8 is effective for improving the efficiency oflight-emission.

FIGS. 1 to 6 are very basic device structures, and the structures of theorganic light-emitting device using the compounds of the presentinvention are not limited to these. It is possible to take the structureof diversified layers, for example, to provide an insulating layer tothe interface between the electrodes and the organic layers, to providean adhesion layer or an interference layer or to compose ahole-transporting layer from two layers having different ionizationpotentials.

The condensed polycyclic compounds represented by the general formula[I] or the general formula [II] used in the present invention areexcellent in an electron-transporting property, a light-emittingproperty and durability compared with conventional compounds, and can beused in any forms shown in FIGS. 1 to 6.

Although the present invention uses the condensed polycyclic compoundsrepresented by the general formula [I] or the general formula [II] asconstituent components for the electron-transporting layer or thelight-emitting layer, already known hole-transporting compounds,light-emitting compounds or electron-transporting compounds can also beused together as necessary.

Examples of these compounds include the followings:

Hole-Transporting Compounds

Electron-Transporting Light-Emitting Materials

Light-Emitting Materials

Light-Emitting Layer Matrix Materials and Electron-TransportingMaterials

Polymer-Based Hole-Transporting Materials

Polymer-Based Light-Emitting Materials and Charge-Transporting Materials

In the organic light-emitting device of the present invention, thelayers containing the condensed polycyclic compounds represented by thegeneral formula [I] or the general formula [II] and the layerscontaining other organic compounds are generally formed into thin filmsby a vacuum deposition process or a coating process in which they aredissolved in a suitable solvent. In particular, when the film is formedby a coating process, it is also possible to form the film incombination with suitable binding resins.

The above-described binding resins can be selected from a wide range ofbinding resins, and include, but not limited to, polyvinylcarbazoleresins, polycarbonate resins, polyester resins, polyallylate resins,polystyrene resins, acrylic resins, methacrylic resins, butyral resins,polyvinylacetal resins, diallylphthalate resins, phenol resins, epoxyresins, silicone resins, polysulfone resins, urea resins and the like.In addition, one of them or a mixture of two or more of them may be usedin the form of a homopolymer or a copolymer.

The materials for the anode preferably have a large work function, andelemental metals such as gold, platinum, nickel, palladium, cobalt,serene, vanadium and alloys thereof and metal oxides such as tin oxides,zinc oxides, indium tin oxides (ITO) and indium zinc oxides can be used.In addition, conductive polymers such as polyaniline, polypyrrole,polythiophene and poyphenylene sulfide can be used. These electrodematerials can be used singly or in combination.

On the other hand, the materials for the cathode preferably have a smallwork function, and elemental metals such as lithium, sodium, potassium,calcium, magnesium, aluminum, indium, silver, lead, tin and chrome andalloys thereof can be used. Metal oxides such as indium tin oxides (ITO)can also be used. The cathode may have one-layered structure or may havea multilayered structure.

The substrates for use in the present invention include, but not limitedto, metal substrates, opaque substrates such as ceramic substrates,transparent substrates such as glass, quartz and plastic sheet.Moreover, it is possible to control the color of emitted light using acolor filter film, a fluorescent color conversion filter film, adielectric reflecting film and the like for the substrate.

Furthermore, a protective layer or a sealing layer can also be providedto the prepared device for the purpose of preventing contact withoxygen, moisture and the like. The protective layer includes aninorganic material film such as a diamond thin film, a metal oxide or ametal nitride; a polymeric film such as a fluororesin, polyparaxylene,polyethylene, a silicone resin and a polystyrene resin; a photo-curableresin or the like. Moreover, the device itself can be covered withglass, a gas-impermeable film, metal or the like and packaged with asuitable sealing resin.

EXAMPLES

The present invention will now be described in detail with reference toexamples, but the present invention is not limited to them.

Example of Synthesis 1 (Synthesis of the Illustrated Compounds No. 1 andNo. 11)

To a three-necked flask of 500 ml, 1.4 g (2.54 mmol) of hexabromobenzene[1], 6.0 g (25.4 mmol) of 9,9-dimethylfluorene-2-boronic acid [2], 160ml of toluene and 80 ml of ethanol were charged and an aqueous solutionof 30 g of sodium carbonate/150 ml of water was dropped under stirringat room temperature in a nitrogen atmosphere, and then 0.9 g (0.78 mmol)of tetrakis(triphenylphosphine)palladium (0) was added. After stirringat room temperature for 30 minutes, the mixture was raised to atemperature of 77° C. and stirred for 20 hours. After the reaction wascompleted, the organic layer was extracted with chloroform, dried withanhydrous sodium sulfate and purified with a silica gel column(hexane+toluene mixed developing solvent), obtaining 0.44 g (yield of17%) of the illustrated compound No. 1 (white crystal) and 1.3 g (yieldof 42%) of No. 11 (white crystal).

Example of Synthesis 2 (Synthesis of the Illustrated Compound No. 2)

To a three-necked flask of 300 ml, 0.5 g (1.03 mmol) of2,3,4,5,6-pentabromotoluene [1], 2.5 g (10.3 mmol) of9,9-dimethylfluorene-2-boronic acid [2], 100 ml of toluene and 50 ml ofethanol were charged and an aqueous solution of 10 g of sodiumcarbonate/50 ml of water was dropped under stirring at room temperaturein a nitrogen atmosphere, and then 0.3 g (0.26 mmol) oftetrakis(triphenylphosphine)palladium (0) was added. After stirring atroom temperature for 30 minutes, the mixture was raised to a temperatureof 7° C. and stirred for 20 hours. After the reaction, the organic layerwas extracted with chloroform before dried with anhydrous sodium sulfateand purified with a silica gel column (hexane+toluene mixed developingsolvent), obtaining 0.54 g (yield of 55%) of the illustrated compoundNo. 2 (white crystal).

Example 1

A device having the structure shown in FIG. 2 was prepared.

On a glass substrate as the substrate 1, indium tin oxide (ITO) as theanode 2 was deposited by a sputtering process in a thickness of 120 nmand ultrasonically cleaned with acetone and isopropyl alcohol (IPA) inthis order, and dried after the cleaning by boiling with IPA. Further,it was cleaned with UV/ozone. The resultant structure is referred to atransparent conductive supporting substrate.

On the transparent conductive supporting substrate, a 0.5% by weightchloroform solution of the compound represented by the followingstructural formula was applied by a spin-coating process to form a filmhaving a thickness of 30 nm, forming the hole-transporting layer 5.

The condensed polycyclic compound represented by the illustratedcompound No. 11 was deposited on the hole-transporting layer 5 by avacuum deposition process in a thickness of 50 nm to form theelectron-transporting layer 6. As for the conditions, the degree of thevacuum at the vapor deposition was 1.0×10⁻⁴ Pa and the speed ofdeposition was 0.2 to 0.3 nm/sec.

A vapor deposition material consisting of aluminum and lithium (lithiumconcentration of 1 atomic %) was used to form a metal layer film havinga thickness of 50 nm on the electron-transporting layer 6 by a vacuumdeposition process, and further by the vacuum deposition process analuminum layer having a thickness of 150 nm was provided to form thecathode 4. As for the conditions, the degree of the vacuum at the vapordeposition was 1.0×10⁻⁴ Pa and the speed of deposition was 1.0 to 1.2nm/sec.

The resultant structure was covered with a protective glass plate in anitrogen atmosphere and sealed with an acrylic resin-based adhesivematerial.

When the thus obtained organic EL device was applied with adirect-current voltage of 10 V using an ITO electrode (anode 2) as apositive electrode and an Al—Li electrode (cathode 4) as a negativeelectrode, the current passed through the device at a current density of12.0 mA/cm² and the light emission of blue color was observed at aluminance of 2,800 cd/m².

In addition, when the voltage was applied for 100 hours whilemaintaining the current density at 10.0 mA/cm², the initial luminance of2,200 cd/m² dropped to 2,000 cd/m² after 100 hours, exhibiting only asmall reduction of luminance.

Examples 2 to 10

Devices were prepared and evaluated in the same manner as in Example 1except that illustrated compounds shown in Table 1 replaced theillustrated compound No. 11. The results are shown in Table 1.

Comparative Examples 1 to 5

Devices were prepared and evaluated in the same manner as in Example 1except that the compounds represented by the structural formulas belowreplaced the illustrated compound No. 11. The results are shown in Table1.

TABLE 1 Comparative compound No. 1

Comparative compound No. 2

Comparative compound No. 3

Comparative compound No. 4

Comparative compound No. 5

Durability Illus- Initial Luminance trated Applied Current Initial After100 Example Compound Voltage Luminance Density Luminance Hours No. No.(V) (cd/m²) (mA/cm²) (cd/m²) (cd/m²) Example 1 11 10 2,800 10.0 2,2002,000 2 1 10 2,600 10.0 1,900 1,600 3 3 10 3,000 10.0 2,400 2,000 4 6 101,900 10.0 1,400 1,100 5 8 10 1,800 10.0 1,500 1,300 6 9 10 2,000 10.01,500 1,200 7 12 10 2,400 10.0 1,900 1,500 8 14 10 950 10.0 800 700 9 1710 1,700 10.0 1,400 1,300 10 21 10 2,200 10.0 1,900 1,500 Comparative 1Comparative 1 10 150 10.0 140 No Light Example Compound Emission 2 2 10170 10.0 150 No Light Emission 3 3 10 300 10.0 250 30 4 4 10 250 10.0240 90 5 5 10 450 10.0 420 150

Example 11

The device shown in FIG. 3 was prepared.

The hole-transporting layer 5 was formed on the transparent conductivesupporting substrate in the same manner as in Example 1.

The condensed polycyclic compound represented by the illustratedcompound No. 1 was deposited on the hole-transporting layer 5 by avacuum deposition process in a thickness of 20 nm to form thelight-emitting layer 3. As for the conditions, the degree of the vacuumat the vapor deposition was 1.0×10⁻⁴ Pa and the speed of deposition was0.2 to 0.3 nm/sec.

Aluminum-trisquinolinol was deposited on the light-emitting layer 3 by avacuum deposition process in a thickness of 40 nm to form theelectron-transporting layer 6. As for the conditions, the degree of thevacuum at the vapor deposition was 1.0×10⁻⁴ Pa and the speed ofdeposition was 0.2 to 0.3 nm/sec.

The device was sealed after the cathode 4 was formed in the same manneras in Example 1.

When the thus obtained device was applied with a direct-current voltageof 8 V using an ITO electrode (anode 2) as a positive electrode and anAl—Li electrode (cathode 4) as a negative electrode, the current havinga current density of 14.0 mA/cm² passed through the device and the lightemission of blue color was observed at a luminance of 5,800 cd/m².

In addition, when the voltage was applied for 100 hours whilemaintaining the current density at 10.0 mA/cm², the initial luminance of4,500 cd/m² dropped to 4,200 cd/m² after 100 hours, exhibiting only asmall reduction of luminance.

Examples 12 to 20

Devices were prepared and evaluated in the same manner as in Example 11except that illustrated compounds shown in Table 2 replaced theillustrated compound No. 1. The results are shown in Table 2.

Comparative Examples 6 to 10

Devices were prepared and evaluated in the same manner as in Example 11except that the comparative compounds No. 1 to 5 replaced theillustrated compound No. 1. The results are shown in Table 2.

TABLE 2 Initial Durability Illustrated Applied Current Initial LuminanceExample Compound Voltage Luminance Density Luminance After 100 No. No.(V) (cd/m²) (mA/cm²) (cd/m²) Hours (cd/m²) Example 11 1 8 5,800 10.04,500 4,200 12 2 8 5,300 10.0 4,200 4,000 13 4 8 2,900 10.0 2,200 2,00014 7 8 4,200 10.0 3,400 3,200 15 10 8 3,000 10.0 2,400 2,000 16 13 83,100 10.0 2,200 2,000 17 15 8 3,600 10.0 2,800 2,300 18 18 8 3,700 10.02,700 2,500 19 20 8 2,800 10.0 2,400 2,100 20 22 8 3,200 10.0 2,5002,200 Comparative 6 Comparative 1 8 350 10.0 300 No Light ExampleCompound Emission 7 2 8 400 10.0 350 No Light Emission 8 3 8 1,000 10.0850 100 9 4 8 750 10.0 650 50 10 5 8 1,500 10.0 1,100 350

Example 21

The device shown in FIG. 3 was prepared.

On the transparent conductive supporting substrate similar to that inExample 1, a 0.5% by weight chloroform solution of the compoundrepresented by the following structural formula was applied by aspin-coating process to form a film having a thickness of 20 nm, formingthe hole-transporting layer 5.

In addition, the condensed polycyclic compound represented by theillustrated compound No. 11 and the fluorene compound represented by theillustrated compound No. FL-6 (weight ratio of 100:1) were deposited bya vacuum deposition process in a thickness of 20 nm to form thelight-emitting layer 3. As for the conditions, the degree of the vacuumat the vapor deposition was 1.0×10⁻⁴ Pa and the speed of deposition was0.2 to 0.3 nm/sec.

Moreover, aluminum-trisquinolinol was deposited by a vacuum depositionprocess in a thickness of 40 nm to form the electron-transporting layer6. As for the conditions for deposition, the degree of the vacuum at thevapor deposition was 1.0×10⁻⁴ Pa and the speed of deposition was 0.2 to0.3 nm/sec.

The device was then sealed after the cathode 4 was formed in the samemanner as in Example 1.

When the thus obtained device was applied with a direct-current voltageof 8 V using an ITO electrode (anode 2) as a positive electrode and anAl—Li electrode (cathode 4) as a negative electrode, the current passedthrough the device at a current density of 13.0 mA/cm² and the lightemission of blue color was observed at a luminance of 13,000 cd/m².

In addition, when the voltage was applied for 100 hours whilemaintaining the current density at 10.0 mA/cm², the initial luminance of10,000 cd/m² dropped to 8,900 cd/m² after 100 hours, exhibiting only asmall reduction of luminance.

Examples 22 to 40

Devices were prepared and evaluated in the same manner as in Example 21except that illustrated fluorene compounds shown in Table 3 replaced theillustrated fluorene compound No. FL-6. The results are shown in Table3.

Comparative Examples 11 to 15

Devices were prepared and evaluated in the same manner as in Example 21except that the comparative compounds No. 1 to 5 replaced theillustrated compound No. 11. The results are shown in Table 3.

TABLE 3 Initial Durability Illustrated Illustrated Applied CurrentInitial Luminance Example Compound Compound Voltage Luminance DensityLuminance After 100 No. No. No. (V) (cd/m²) (mA/cm²) (cd/m²) Hours(cd/m²) Example 21 11 FL-6 8 13,000 10.0 10,000 9,000 22 11 FL-1 811,000 10.0 8,500 8,000 23 11 FL-2 8 11,000 10.0 8,000 7,000 24 11 FL-38 8,500 10.0 7,500 6,500 25 11 FL-4 8 13,000 10.0 9,500 7,500 26 11 FL-58 12,000 10.0 9,000 7,000 27 11 FL-7 8 7,000 10.0 6,000 5,500 28 11 FL-88 7,500 10.0 6,500 6,000 29 11 FL-9 8 12,000 10.0 10,000 9,000 30 11FL-10 8 6,500 10.0 6,000 5,500 31 11 FL-11 8 15,000 10.0 12,000 11,00032 11 FL-12 8 9,000 10.0 8,000 6,500 33 11 FL-13 8 7,000 10.0 6,5006,000 34 11 FL-14 8 8,000 10.0 6,500 5,500 35 11 FL-15 8 11,000 10.09,000 8,000 36 11 FL-16 8 16,000 10.0 13,000 11,000 37 11 FL-17 8 13,00010.0 11,000 9,500 38 11 FL-18 8 9,500 10.0 8,000 6,500 39 11 FL-19 87,500 10.0 6,000 5,000 40 11 FL-20 8 6,500 10.0 6,000 5,000 Comparative11 Comparative 1 1 8 2,500 10.0 2,000 300 Example 12 Compound 2 2 82,000 10.0 15,000 No Light Emission 13 3 3 8 3,000 10.0 25,000 600 14 44 8 2,500 10.0 2,000 400 15 5 5 8 3,500 10.0 3,000 1,000

Example 41

The device shown in FIG. 3 was prepared.

On the transparent conductive supporting substrate similar to that inExample 1, a 0.5% by weight chloroform solution of the compoundrepresented by the following structural formula was applied by aspin-coating process to form a film having a thickness of 20 nm, formingthe hole-transporting layer 5.

In addition, the condensed polycyclic compound represented by theillustrated compound No. 2 and the compound represented by the followingstructural formula (weight ratio of 100:5) were deposited by a vacuumdeposition process in a thickness of 20 nm to form the light-emittinglayer 3. As for the conditions for deposition, the degree of the vacuumat the vapor deposition was 1.0×10⁻⁴ Pa and the speed of deposition was0.2 to 0.3 nm/sec.

Moreover, bathophenanthroline (BPhen) was deposited by a vacuumdeposition process in a thickness of 40 nm to form theelectron-transporting layer 6. As for the conditions for deposition, thedegree of the vacuum at the vapor deposition was 1.0×10⁻⁴ Pa and thespeed of deposition was 0.2 to 0.3 nm/sec.

The device was then sealed after the cathode 4 was formed in the samemanner as in Example 1.

When the thus obtained device was applied with a direct-current voltageof 8 V using an ITO electrode (anode 2) as a positive electrode and anAl—Li electrode (cathode 4) as a negative electrode, the current passedthrough the device at a current density of 9.5 mA/cm² and the lightemission of green color was observed at a luminance of 7,000 cd/m².

In addition, when the voltage was applied for 100 hours whilemaintaining the current density at 7.0 mA/cm², the initial luminance of5,000 cd/m² dropped to 4,500 cd/m² after 100 hours, exhibiting only asmall reduction of luminance.

Examples 42 to 50

Devices were prepared and evaluated in the same manner as in Example 41except that illustrated compounds shown in Table 4 replaced theillustrated compound No. 2. The results are shown in Table 4.

Comparative Examples 16 to 20

Devices were prepared and evaluated in the same manner as in Example 41except that the comparative compounds No. 1 to 5 replaced theillustrated compound No. 2. The results are shown in Table 4.

TABLE 4 Initial Durability Illustrated Applied Current Initial LuminanceExample Compound Voltage Luminance Density Luminance After 100 No. No.(V) (cd/m²) (mA/cm²) (cd/m²) Hours (cd/m²) Example 41 2 8 7,000 7.05,000 4,500 42 3 8 6,500 7.0 5,000 4,000 43 5 8 8,000 7.0 6,500 6,000 446 8 7,000 7.0 6,000 5,000 45 13 8 6,000 7.0 5,000 4,500 46 15 8 8,5007.0 7,500 6,500 47 16 8 7,000 7.0 6,500 6,000 48 19 8 4,500 7.0 4,0003,500 49 20 8 5,000 7.0 4,000 3,000 50 22 8 6,500 7.0 5,500 4,500Comparative 16 Comparative 1 8 900 7.0 800 100 Example 17 Compound 2 8650 7.0 600 No Light Emission 18 3 8 1,500 7.0 1,000 300 19 4 8 1,0007.0 850 100 20 5 8 2,000 7.0 1,500 550

Example 51

The device shown in FIG. 1 was prepared.

On the transparent conductive supporting substrate similar to that inExample 1, a solution in which 0.050 g of the condensed polycycliccompound represented by the illustrated compound No. 1 and 1.00 g ofpoly-N-vinylcarbazole (weight average molecular weight=63,000) weredissolved in 80 ml of chloroform was applied by a spin-coating process(the number of revolutions=2,000 rpm) to form a film having a thicknessof 120 nm, forming the organic layer (light-emitting layer 3).

The device was then sealed after the cathode 4 was formed in the samemanner as in Example 1.

When the thus obtained device was applied with a direct-current voltageof 10 V using an ITO electrode (anode 2) as a positive electrode and anAl—Li electrode (cathode 4) as a negative electrode, the current passedthrough the device at a current density of 7.7 mA/cm² and the lightemission of blue color was observed at a luminance of 1,400 cd/m².

In addition, when the voltage was applied for 100 hours whilemaintaining the current density at 5.0 mA/cm² in a nitrogen atmosphere,the initial luminance of 950 cd/m² dropped to 900 cd/m² after 100 hours,exhibiting only a small reduction of luminance.

Examples 52 to 55

Devices were prepared and evaluated in the same manner as in Example 51except that illustrated compounds shown in Table 5 replaced theillustrated compound No. 1. The results are shown in Table 5.

Comparative Examples 21 to 25

Devices were prepared and evaluated in the same manner as in Example 51except that the comparative compounds No. 1 to 5 replaced theillustrated compound No. 1. The results are shown in Table 5.

TABLE 5 Initial Durability Illustrated Applied Current Initial LuminanceExample Compound Voltage Luminance Density Luminance After 100 No. No.(V) (cd/m²) (mA/cm²) (cd/m²) Hours (cd/m²) Example 51 1 10 1,400 5.0 950900 52 2 10 1,200 5.0 900 800 53 11 10 1,500 5.0 1,200 1,100 54 17 101,400 5.0 1,000 950 55 19 10 1,300 5.0 1,000 850 Comparative 16Comparative 1 10 250 5.0 200 No Light Example Compound Emission 17 2 10150 5.0 100 No Light Emission 18 3 10 350 5.0 300 No Light Emission 19 410 300 5.0 250 No Light Emission 20 5 10 550 5.0 450 100

As described above by illustrating embodiments and examples, the organiclight-emitting devices using the condensed polycyclic compoundsrepresented by the general formula [I] or the general formula [II]provide the light-emission having high luminance at a low appliedvoltage and are also excellent in durability. Particularly, the organiclayers containing the condensed polycyclic compounds of the presentinvention are excellent as an electron-transporting layer as well as alight-emitting layer.

Moreover, it is possible to prepare the devices by using a vacuumdeposition process, casting process or the like, and the devices havinga large area can be prepared easily at a relatively low cost.

1. A condensed polycyclic compound represented by the followingstructural formula:


2. A condensed polycyclic compound represented by the followingstructural formula:


3. An organic light-emitting device comprising a pair of electrodesconsisting of an anode and a cathode and one or a plurality of organiccompound-containing layers sandwiched between the pair of electrodes,wherein at least one layer of the organic compound-containing layerscontains at least the condensed polycyclic compound according toclaim
 1. 4. An organic light-emitting device comprising a pair ofelectrodes consisting of an anode and a cathode and one or a pluralityof organic compound-containing layers sandwiched between the pair ofelectrodes, wherein at least one layer of the organiccompound-containing layers contains at least the condensed polycycliccompound according to claim
 2. 5. The organic light-emitting deviceaccording to claim 3, wherein at least one layer of the organiccompound-containing layers containing the condensed polycyclic compoundis an electron-transporting layer or a light-emitting layer.
 6. Theorganic light-emitting device according to claim 4, wherein at least onelayer of the organic compound-containing layers containing the condensedpolycyclic compound is an electron-transporting layer or alight-emitting layer.
 7. The organic light-emitting device according toclaim 3, wherein at least one of the layers containing the condensedpolycyclic compound is a light-emitting layer containing a fluorenecompound represented by general formula [VIII]:

wherein R₉ and R₁₀ are the same or different and are each independentlyhydrogen or a group selected from the group consisting of alkyl,aralkyl, aryl and heterocyclic, each having no substituent or asubstituent; any pair of R₉ combined to their respective fluorenestructures are the same or different to each other; any pair of R₁₀combined to their respective fluorene structures are the same ordifferent to each other; R₁₁ and R₁₂ are the same or different and areeach independently hydrogen, halogen, cyano or a group selected from thegroup consisting of alkyl, aralkyl, aryl and heterocyclic, each havingno substituent or a substituent; any pair of R₁₁ combined to theirrespective fluorene structures are the same or different to each other;any pair of R₁₂ combined to their respective fluorene structures are thesame or different to each other; Ar₁₂, Ar₁₃, Ar₁₄ and Ar₁₅ are the sameor different and are each independently a group selected from the groupconsisting of aromatic, heterocyclic, condensed polycyclic aromatic andcondensed polycyclic heterocyclic, each having no substituent or asubstituent, and Ar₁₂ and Ar₁₄ can be bonded to Ar₁₃ and Ar₁₅respectively to form a ring; and n is an integer from 1 to
 10. 8. Theorganic light-emitting device according to claim 4, wherein at least oneof the layers containing the condensed polycyclic compound is alight-emitting layer containing a fluorene compound represented bygeneral formula [VIII]:

wherein R₉ and R₁₀ are the same or different and are each independentlyhydrogen, halogen, cyano or a group selected from the group consistingof alkyl, aralkyl, aryl and heterocyclic, each having no substituent ora substituent; any pair of R₉ combined to their respective fluorenestructures are the same or different to each other; any pair of R₁₀combined to their respective fluorene structures are the same ordifferent to each other; R₁₁ and R₁₂ are the same or diffenrent and areeach independently hydrogen, halogen, cyano or a group selected from thegroup consisting of alkyl, aralkyl, aryl and heterocyclic, each havingno substituent or a substituent; any pair of R₁₁ combined to theirrespective fluorene structures are the same or different to each other;any pair of R₁₂ combined to their respective fluorene structures are thesame or different to each other; Ar₁₂, Ar₁₃, Ar₁₄ and Ar₁₅ are the sameor different and are each independently a group selected from the groupconsisting of aromatic, heterocyclic, condensed polycyclic aromatic andcondensed polycyclic heterocyclic, each having no substituent or asubstituent, and Ar₁₂ and Ar₁₄ can be bonded to Ar₁₃ and Ar₁₅respectively to form a ring; and n is an integer from 1 to
 10. 9. Theorganic light-emitting device according to claim 3, wherein at least oneof the layers containing the condensed polycyclic compound is alight-emitting layer containing a fluorene compound represented bygeneral formula [IX]:

wherein R₁₃ and R₁₄ are the same or different and are each independentlyhydrogen or a group selected from the group consisting of alkyl,aralkyl, aryl and heterocyclic, each having no substituent or asubstituent; any pair of R₁₃ combined to their respective fluorenestructures are the same or different to each other; any pair of R₁₄combined to their respective fluorene structures are the same ordifferent to each other; R₁₅ and R₁₆ are the same or different and areeach independently hydrogen, halogen, cyano or a group selected from thegroup consisting of alkyl, aralkyl, aryl and heterocyclic, each havingno substituent or a substituent; any pair of R₁₅ combined to theirrespective fluorene structures are the same or different to each other;any pair of R₁₆ combined to their respective fluorene structures are thesame or different to each other; Ar₁₆ and Ar₁₇ are the same or differentand are each independently a divalent group selected from the groupconsisting of divalent aromatic and divalent heterocyclic, each havingno substituent or a substituent; Ar₁₈, Ar₁₉, Ar₂₀ and Ar₂₁ are the sameor different and are each independently a group selected from the groupconsisting of aromatic, heterocyclic, condensed polycyclic aromatic andcondensed polycyclic heterocyclic, each having no substituent or asubstituent, and Ar₁₈ and Ar₂₀ can be bonded to Ar₁₉ and Ar₂₁respectively to form a ring; and m is an integer from 1 to
 10. 10. Theorganic light-emitting device according to claim 4, wherein at least oneof the layers containing the condensed polycyclic compound is alight-emitting layer containing a fluorene compound represented bygeneral formula [IX]:

wherein R₁₃ and R₁₄ are the same or different and are each independentlyhydrogen or a group selected from the group consisting of alkyl,aralkyl, aryl and heterocyclic, each having no substituent or asubstituent; any pair of R₁₃ combined to their respective fluorenestructures are the same or different to each other; any pair of R₁₄combined to their respective fluorene structures are the same ordifferent to each other; R₁₅ and R₁₆ are the same or different and areeach independently hydrogen, halogen, cyano or a group selected from thegroup consisting of alkyl, aralkyl, aryl and heterocyclic, each havingno substituent or a substituent; any pair of R₁₅ combined to theirrespective fluorene structures are the same or different to each other;any pair of R₁₆ combined to their respective fluorene structures are thesame or different to each other; Ar₁₆ and Ar₁₇ are the same or differentand are each independently a divalent group selected from the groupconsisting of divalent aromatic and divalent heterocyclic, each havingno substituent or a substituent; Ar₁₈, Ar₁₉, Ar₂₀ and Ar₂₁ are the sameor different and are each independently a group selected from the groupconsisting of aromatic, heterocyclic, condensed polycyclic aromatic andcondensed polycyclic heterocyclic, each having no substituent or asubstituent, and Ar₁₈ and Ar₂₀ can be bonded to Ar₁₉ and Ar₂₁respectively to form a ring; and m is an integer from 1 to 10.